High-density multi-layer optical disc, method for recording data thereon on layer-by-layer basis, and method for managing spare areas thereof

ABSTRACT

A high-density multi-layer optical disc, a method for recording data thereon on a layer-by-layer basis, and a method for managing spare areas thereof. In a high-density multi-layer optical disc, having a plurality of recording layers formed thereon, such as a Blu-ray disc rewritable (BD-RE) dual layer, management information is recorded and managed appropriately to the multiple layers so that data can be recorded in a state where the recording layers are linked to each other or the recording layers are separated from each other. Inner and outer spare areas are separately assigned to each of the recording layers formed on the high-density multi-layer optical disc. The management information is recorded and managed appropriately to the multiple layers so that the data can be recorded in a state where the spare areas of the recording layers must be used together irrespective of the recording layers or used separately on the layer-by-layer basis. The recording layers can be effectively used and managed, and the spare areas separately assigned to the respective recording layers can be effectively used and managed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a high density multi-layer optical discon which multiple layers are formed, a method for recording data thereonon a layer-by-layer basis, and a method for managing spare areasthereof.

2. Description of the Related Art

As standardization of a high-density rewritable optical disc, e.g.; aBlu-ray disc rewritable (BD-RE), capable of storing high-quality videoand audio rapidly progresses, it is expected that related products willbe developed, commercialized and supplied.

A conventional BD-RE single layer 100 is shown in FIG. 1. As shown inFIG. 1, there is a distance of approximately 0.1 mm between a recordinglayer and the surface of a transparent film being arranged between therecording layer and an objective lens (OL) 11 of an optical pick-up.

When an optical disc apparatus for reading and reproducing data recordedon the recording layer of the BD-RE single layer 100 or recording datathereon determines that a defect is detected on the layer 100 whileperforming a data recording operation, the optical disc apparatusrecords the data in an inner spare area (ISA) or outer spare area (OSA)separately assigned to a data area as shown in FIG. 2, in place of adata area.

Further, the optical disc apparatus generates a defect list (DFL) entryneeded for identifying a cluster associated with a recording unit block{RUB} recorded in the spare area in place of a data area, and performs arecording and management operation for the generated DFL entry.

As shown in FIG. 2, management information associated with the spareareas is contained and recorded in a field of rewritable disc definitionstructure (DDS) information of a lead-in area. The DDS informationincludes information items associated with the first physical sectornumber (PSN) of the DFL (P_DFL), a location of a logical sector number(LSN) 0 of in user data area, the last LSN of the user data area, a sizeof the ISA (ISA_size), a size of the OSA (OSA_Size), spare area fullflags indicating whether the respective spare areas are full, the lastverified address (LVA) pointer, etc.

The spare area full flags are recorded by one byte consisting of a 1-bitISA full flag, a 1-bit OSA full flag and 6-bit reserved informationassigned to a reserved area.

As described above, when the defect is detected in the data area whilethe optical disc apparatus records data in the data area, the opticaldisc apparatus searches for the spare area full flags contained andrecorded in the DDS information field, selects the ISA or OSA in whichthe data can be recorded, and performs a sequence of data recordingoperations for recording the data in the selected spare area.

A high-density dual-layer optical disc, i.e., a BD-RE dual layer,capable of recording twice as much video and audio data as the BD-REsingle layer, has been developed. As shown in FIG. 3, there is adistance d2 between the first recording layer (Layer 0) and the secondrecording layer (Layer 1) formed in the BD-RE dual layer 200. The firstand second recording layers are formed at a location, within the BD-REdual layer 200, having a bias toward the OL 11 of the optical pick-up.

The first and second recording layers of the BD-RE dual layer 200 arelinked to each other so that the large-capacity data can be recorded.The ISA and OSA can be separately assigned to each of the data areasassociated with the first and second recording layers. However, there isnot yet provided a method for efficiently employing the first and secondrecording layers of the BD-RE dual layer 200 on a layer-by-layer basis.Moreover, there is not yet provided a method for efficiently employingand managing a plurality of spare areas separately assigned to eachrecording layer.

SUMMARY OF THE INVENTION

Therefore, it is one object of the present invention to provide ahigh-density multi-layer optical disc such as a Blu-ray disc rewritable(BD-RE) dual layer, and a method for recording data thereon on alayer-by-layer basis, which can use a plurality of recording layersformed on the disc together or separately and hence can efficientlyrecord and manage the data of the recording layers.

It is another object of the present invention to provide a high-densitymulti-layer optical disc such as a Blu-ray disc rewritable (BD-RE) duallayer, and a method for managing spare areas thereof, which can assigninner and outer spare areas to each of multiple recording layers formedon the disc, and use the spare areas assigned to the respectiverecording layers together or separately.

In accordance with one aspect of the present invention, the above andother objects can be accomplished by the provision of a high-densitymulti-layer optical disc having a plurality of recording layers formedthereon, comprising: at least one of spare areas separately assigned toeach of the recording layers, the spare areas being usable when a defectis detected and to be managed; and at least one specified area containedin at least one of recording layers, the specified area havingmanagement information indicating whether the recording layers must beused together or separately.

In accordance with another aspect of the present invention, there isprovided a high-density multi-layer optical disc having a plurality ofrecording layers formed thereon, comprising: an inner spare area and anouter spare area assigned to each data area, while each data area beingassigned to each of the recording layers; and management information,additionally recorded in a lead-in area, indicating whether the spareareas of the recording layers must be used together irrespective of therecording layers or used separately on a layer-by-layer basis.

In accordance with another aspect of the present invention, there isprovided a method for recording data on a high-density multi-layeroptical disc on a layer-by-layer basis, comprising the steps of: (a)reading disc definition structure (DDS) information recorded in at leastone specified area of the high-density multi-layer optical disc, andstoring the read information in a memory, wherein the disc definitionstructure information includes control information for indicatingwhether recording layers must be used together or separately; (b)determining whether to use the recording layers together or separatelybased on the control information; and (c) performing the data recordingoperation and/or a defect management operation according to a result ofthe determination.

In accordance with another aspect of the present invention, there isprovided a method for managing spare areas of a high-density multi-layeroptical disc, comprising the steps of: (a) detecting a defect within adata area of the high-density multi-layer optical disc while the data isrecorded in the data area; (b) confirming spare area managementinformation read from a lead-in area of the high-density multi-layeroptical disc, when the defect is detected; and (c) determining whetherspare areas separately assigned to a current recording layer must beused together with other spare areas separately assigned to anotherrecording layer or only the spare areas of the current recording layermust be used separately, according to the confirmed spare areamanagement information.

In accordance with another aspect of the present invention, there isprovided a method for managing spare areas of a high-density multi-layeroptical disc, comprising the steps of: (a) reading control informationstored in an area of the optical recording medium, said controlinformation including indication information for indicating whether ornot at least two layers are associated with each other to record data toor read data from the recording medium; and (b) controlling recording orreading based on the control information.

In accordance with another aspect of the present invention, there isprovided a method for managing spare areas of a high-density multi-layeroptical disc, comprising the steps of: (a) recording control informationon an area of the optical recording medium, said control informationincluding indication information for indicating whether or not at leasttwo recording layers are associated with each other for data to berecorded or read; and (b) controlling recording or reading based on thecontrol information.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, illustrate the preferred embodiments ofthe invention, and together with the description, serve to explain theprinciples of the present invention.

FIG. 1 is a view illustrating the structure of a conventional Blu-raydisc rewritable (BD-RE);

FIG. 2 is a table illustrating disc definition structure (DDS)information recorded and managed in a lead-in area of the conventionalBD-RE;

FIG. 3 is a view illustrating the structure of a high-density dual-layeroptical disc;

FIG. 4 is a view illustrating a state where. disc information (DI) anddisc definition structure (DDS) information are contained in lead-in andlead-out areas of the high-density dual-layer optical disc in accordancewith the present invention;

FIG. 5 is a table illustrating the DDS information recorded and managedin each of the lead-in and lead-out areas of the high-density dual-layeroptical disc in accordance with the present invention;

FIG. 6 is a view illustrating the configuration of an optical discapparatus to which a method for recording data on the disc on alayer-by-layer basis and managing spare areas of the disc is applied inaccordance with the present invention;

FIG. 7 is a flowchart illustrating a method for recording data on thehigh-density dual-layer optical disc on the layer-by-layer basis inaccordance with the present invention;

FIG. 8 is a flowchart illustrating a method for managing spare areas ofthe high-density dual-layer optical disc in accordance with the presentinvention; and

FIG. 9 is another table illustrating the DDS information based on thespare area management method in accordance with the present invention.

Features, elements, and aspects of the invention that are referenced bythe same numerals in different figures represent the same, equivalent,or similar features, elements, or aspects in accordance with one or moreembodiments.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A high-density multi-layer optical disc, a method for recording datathereon on a layer-by-layer basis, and a method for managing spare areasthereof in accordance with preferred embodiments of the presentinvention will be described in detail with reference to the annexeddrawings.

First, as shown in FIG. 4, a lead-in area is assigned to the firstrecording layer (Layer 0) and a lead-out area is assigned to the secondrecording layer (Layer 1) in the high-density multi-layer optical disc,e.g., a Blu-ray disc rewritable (BD-RE) dual layer 200, in accordancewith the present invention. The first inner spare area (ISA0) and firstouter spare area (OSA0) are separately assigned to a data area for thefirst recording layer. The second ISA (ISA1) and second OSA (OSA1) areseparately assigned to a data area for the second recording layer.

Management information needed for managing a plurality of spare areasseparately assigned to the data area for each recording layer and defectmanagement address (DMA) information needed for managing a defect arerewritable disc definition structure (DDS) information. The rewritableDDS information can be recorded and managed in the lead-in area of thefirst recording layer and the lead-out area of the second recordinglayer.

As shown in FIG. 5, the DDS information includes information itemsassociated with the first physical sector number (PSN) of a defect list(DFL) for the first recording layer (Layer 0) (P_DFL0), the first PSN ofa DFL for the second recording layer (Layer 1) (P_DFL1), a location of alogical sector number (LSN) 0 of a user data area for the firstrecording layer, a location of a logical sector number (LSN) 0 of a userdata area for the second recording layer, the last LSN of the user dataarea for the first recording layer, the last LSN of the user data areafor the second recording layer, a size of the first ISA (ISA0_size), asize of the second OSA (OSA1_size), spare area full flags indicatingwhether the respective spare areas are full, the last verified address(LVA) pointer for the first recording layer, the LVA pointer for thesecond recording layer, etc.

The DDS information contains the spare area management information andDMA information on the layer-by-layer basis so that the first and secondrecording layers can be used and managed separately.

Disc information (DI), contained and recorded in the lead-in area alongwith the DDS information, includes layer separate use(Layer_Separate_Use) information indicating whether the first and secondrecording layers are used separately or together. For example, the layerseparate use information can be recorded and managed as a 1-bit flag.Where Layer_Separate_Use=“1”, the optical disc apparatus separates therespective recording layers to record data on only an arbitraryrecording layer. Meanwhile, where Layer_Separate Use=“0”, the opticaldisc apparatus links the respective recording layers to consecutivelyrecord data on the linked recording layers.

The spare area full flags contained in the DDS information fieldincludes the first inner spare area full flag (b0) using one bit, thefirst outer spare area full flag (b1) using one bit, the second innerspare area full flag (b2) using one bit, the second outer spare areafull flag (b3) using one bit, and 2-bit area state information (b5b4).

For example, where “b5b4”=00, the spare area state information indicatesthat the first inner and outer spare areas assigned to the firstrecording layer and the second inner and outer spare areas assigned tothe second recording layer must be used and managed, separately on thelayer-by-layer basis. Meanwhile, where “b5b4”=11, the spare area stateinformation indicates that the first inner and outer spare areasassigned to the first recording layer and the second inner and outerspare assigned to the second recording layer must be used and managedtogether.

Further, where “b5b4”=01, the spare area state information indicatesthat the first inner and outer spare areas assigned to the firstrecording layer are full. Meanwhile, where “b5b4”=10, the spare areastate information indicates that the second inner and outer spare areasseparately assigned to the second recording layer are full.

Thus, the optical disc apparatus confirms the spare area stateinformation contained and recorded in the above-described DDSinformation field. Then, the optical disc apparatus uses the multiplespare areas assigned to the first and second recording layers separatelyor together on the basis of the confirmed information.

FIG. 6 is a view illustrating a configuration of the optical discapparatus to which a method for managing the spare areas of the disc isapplied in accordance with the present invention. For example, anoptical disc apparatus such as a video disc recorder (VDR) for recordingor reproducing data of a BD-RE dual layer includes an optical pick-up 50for reading data recorded on a high-density multi-layer optical disc 200such as the BD-RE dual layer or recording a data stream corresponding toa processed signal; a VDR system 51 for performing a signal processingoperation so that a signal of the data read by the optical pick-up 50can be reproduced or converting an externally inputted data stream intoa data stream appropriate for recording; and an encoder 52 for encodingan externally inputted analog signal and outputting the encoded analogsignal to the VDR system.

FIG. 7 is a flowchart illustrating a method for recording data on thehigh-density dual-layer optical disc on layer-by-layer basis inaccordance with the present invention.

As shown in FIG. 7, where the high-density multi-layer optical disc,e.g., the BD-RE dual layer 200, is inserted and loaded in the VDR system51 of the optical disc apparatus, a sequence of optical disc loadingoperations is performed and a lead-in area of the optical disc isaccessed at step S10:

Then, the VDR system 51 reads disc information (DI) and disc definitionstructure (DDS) information recorded in the lead-in area and then storesthe read information in an internal memory (not shown) provided in theoptical disc apparatus at step S11. As shown in FIG. 5, the DDSinformation contains spare area management information on thelayer-by-layer basis and defect management address (DMA) information.

Then, upon receiving a data recording request from a user, the VDRsystem 51 searches for and confirms layer separate use information(Layer_Separate_Use) contained and recorded in the DI or the DDS at stepS12.

It is determined whether Layer_Separate_Use=“1” at step S13. IfLayer_Separate_Use=“1”, the VDR system 51 sets an operating mode to alayer separate use mode for using the recording layers separately atstep S14 and records data on only an arbitrary recording layer on thebasis of the user's request at step S15.

At this time, the VDR system 51 selectively refers to only managementinformation associated with a corresponding recording layer in the sparearea management information on the layer-by-layer basis and the DMAinformation. If a defect is detected within a data area of the recordinglayer, data is recorded in only the spare areas for the recording layer,separately assigned to the recording layer, in place of the data area. Asequence of defect management operations for the corresponding recordinglayer is performed to record and manage a defect list (DFL) entry andDMA information at step S16.

On the other hand, if Layer_Separate_Use=“0”, the VDR system 51 sets anoperating mode to a layer linkage use mode for linking the recordinglayers and recording data on the linked recording layers at step S17.Then, the VDR system 51 links the recording layers to consecutivelyrecord data, corresponding to the data recording request from the user,on the linked recording layers at step S18.

The VDR system 51 refers to all the spare area management information onthe layer-by-layer basis and the DMA information contained in the DDSinformation field. If the defect is detected within the data area of acorresponding recording layer, the VDR system 51 records data using thespare areas separately assigned to one recording layer, or other spareareas separately assigned to another recording layer. Thus, the VDRsystem 51 performs the defect management operation for the multiplelayers to record and manage the DFL and DMA management information atstep S19.

For reference, the layer separate use information (Layer_Separate_Use)can be contained and recorded in the DDS information field. A value ofthe layer separate use information can be arbitrarily set by a userholding the optical disc apparatus or an optical disc manufacturer, orcan be fixed to a specified value.

Optionally, the DI containing the layer separate use information can berecorded and managed in only the lead-in area is of the first recordinglayer.

FIG. 8 is a flowchart illustrating a method for managing the spare areasof the high-density dual-layer optical disc in accordance with thepresent invention.

As shown in FIG. 8, where the high-density multi-layer optical disc,e.g., the BD-RE dual layer 200, is inserted and loaded in the VDR system51 of the optical disc apparatus, a sequence of optical disc loadingoperations is performed and a lead-in area of the optical disc isaccessed at step S20.

Then, the VDR system 51 reads disc information (DI) and disc definitionstructure (DDS) information recorded in the lead-in area and then storesthe read information in an internal memory (not shown) provided in theoptical disc apparatus at step S21. As shown in FIG. 5, the DDSinformation contains management information needed for managing aplurality of spare areas on the layer-by-layer basis and defectmanagement address (DMA) information, so management informationassociated with spare areas separately assigned to each of the recordinglayers is stored in the memory.

Then, upon receiving a data recording request from the user at step S22,the VDR system 51 performs a data recording operation corresponding tothe data recording request at step S23. Further, upon receiving anotherrequest, the VDR system 51 performs a sequence of operationscorresponding to another request at step S24.

Then, upon detecting a defect within the data area of a correspondingrecording layer while the data recording operation is performed inresponse to the user's request at step S25, the VDR system 51 searchesfor and confirms spare area full flags contained and recorded in the DDSinformation field. At this time, the VDR system 51 searches for sparearea state information shown in FIG. 5 at step S26.

Then, the spare areas of the respective recording layers are usedtogether or separately on the basis of the confirmed spare area stateinformation (b5b4) at step S27. For example, where “b5b4”=00, the sparearea state information indicates that the first inner and outer spareareas assigned to the first recording layer and the second inner andouter spare areas assigned to the second recording layer must be usedand managed separately on the layer-by-layer basis. Meanwhile, where“b5b4”=11, the spare area state information indicates that the firstinner and outer spare areas assigned to the first recording layer andthe second inner and outer spare areas assigned to the second recordinglayer must be together used and managed.

Further, where “b5b4”=01, the spare area state information indicatesthat the first inner and outer spare areas assigned to the firstrecording layer are full. Meanwhile, where “b5b4”=10, the spare areastate information indicates that the second inner and outer spare areasseparately assigned to the second recording layer are full. In thesecases, a sequence of operations performed to generate and output anon-screen display (OSD) image for a message indicating that the spareareas of another recording layer must by used or that a recording erroroccurs so that the user can confirm the message.

The VDR system 51 generates a DF L entry needed for identifying acluster associated with a recording unit block (RUB) recorded in a sparearea and then manages the generated DFL entry at step S28. Then, the VDRsystem 51 determines whether the data recording operation has beencompleted at step S29. If the data recording operation has beencompleted, the data recording operation is terminated. Otherwise, thedata recording operation is continuously performed.

FIG. 9 is another table illustrating the DDS information based on thespare area management method in accordance with the present invention.The spare area state information is contained and recorded in the DDSinformation field. Optionally, the spare area state information can becontained and recorded in another recording field, e.g., a reserved areacontained in the DDS information field, different from a fieldassociated with the spare area full flags.

When the defect is detected within the data area and simultaneously datato be recorded in a spare area is real-time audio/video (A/V) data, thespare area state information can be used as information indicating thata data recording operation for the spare area can be omitted. Further,when the defect is detected within the data area and simultaneously datato be recorded in the spare area is computer file data, the spare areastate information is used as information indicating that a datarecording operation for the spare area can be performed.

For reference, the DDS information can be contained and recorded in thelead-out area as well as the lead-in area.

The method for recording data on the layer-by-layer basis canadditionally use the spare area management method. In the flowchartillustrating the data recording method on the layer-by-layer basis asshown in FIG. 7, the VDR system 51 links the recording layers toconsecutively record data on the linked recording layers at the abovesteps S17 to S19 if Layer_Separate_Use=“0” as a result of thedetermination at the above step S13. When the defect is detected withinthe data area of the corresponding recording layer while the datarecording operation is performed in response to the user's request, theabove-described spare area management method can be efficiently applied.That is, if the defect is detected, the above steps S18 and S19 shown inFIG. 7 can be replaced with the above steps S23 and S25-S29 shown inFIG. 8.

As apparent from the above description, the present invention provides ahigh-density multi-layer optical disc, a method for recording datathereon on a layer-by-layer basis, and a method for managing spare areasthereof, which can effectively use and manage a plurality of recordinglayers formed on the disc and can effectively use and manage a pluralityof spare areas separately assigned to each of the recording layers.

The preferred embodiments of the present invention have been disclosedfor illustrative purposes. Those skilled in the art will appreciate thatvarious modifications, additions and substitutions are possible, withoutdeparting from the scope and spirit of the invention as disclosed in theaccompanying claims.

1. A high-density multi-layer optical disc having a plurality ofrecording layers formed thereon, the optical disc comprising: at leastone spare area assigned to each of the recording layers, respectively,the spare areas being usable to manage one or more defects detected inthe recording layers; and at least one specified area contained in atleast one of recording layers, the specified area having managementinformation indicating whether use of the spare areas for defectmanagement is restricted to respective assigned layers or islayer-unrestricted.
 2. The high-density multi-layer optical disc as setforth in claim 1, wherein said at least one specified area is containedin a lead-in area or lead-out area separately assigned to each recordinglayer, and the management information is contained and recorded in afield of disc definition structure (DDS) information and/or discinformation (DI) recorded and managed in the lead-in area or lead-outarea.
 3. The high-density multi-layer optical disc as set forth in claim2, wherein the DDS information comprises spare area managementinformation for indicating how the spare areas are respectively assignedto the recording layers, and a defect address management (DAM)information needed for managing a defect list (DFL), the DDS informationbeing recorded on at least one of the recording layers.
 4. Thehigh-density multi-layer optical disc as set forth in claim 3, whereinthe spare area management information comprises information indicating asize of an inner spare area or outer spare area respectively assigned toa data area of each recording layer, and spare area full flaginformation indicating whether or not a corresponding spare area isfull.
 5. The high-density multi-layer optical disc as set forth in claim4, wherein the spare area full flag information comprises information ofat least two bits indicating whether the spare areas of the recordinglayers must be used together irrespective of the recording layers orused separately on a layer-by-layer basis.
 6. The high-densitymulti-layer optical disc as set forth in claim 4, wherein the DDSinformation comprises information of at least two bits indicatingwhether the spare areas of the recording layers must be used togetherirrespective of the recording layers or used separately on alayer-by-layer basis, separated from the spare area full flaginformation indicating whether each of the spare areas is full.
 7. Thehigh-density multi-layer optical disc as set forth in claim 2, whereinthe DI comprises layer separate use information indicating whether therecording layers must be used together or separately at the time ofperforming the data recording operation.
 8. The high-density multi-layeroptical disc as set forth in claim 7, wherein the layer separate useinformation is recorded and managed as a 1-bit flag.
 9. A high-densitymulti-layer optical disc having a plurality of recording layers formedthereon, comprising: an inner spare area and outer spare area assignedto each data area, while each data area being assigned to each of therecording layers; and management information, additionally recorded in alead-in area, indicating whether the spare areas of the recording layersmust be used together irrespective of the recording layers or usedseparately on a layer-by-layer basis.
 10. The high-density multi-layeroptical disc as set forth in claim 9, wherein the management informationis contained and recorded in a field of disc definition structure (DDS)information contained and recorded in the lead-in area.
 11. Thehigh-density multi-layer optical disc as set forth in claim 10, whereinthe DDS information comprises information indicating a size of the innerspare area or outer spare area respectively assigned to the data areafor each recording layer, and spare area full flag informationindicating whether or not a corresponding spare area is full.
 12. Thehigh-density multi-layer optical disc as set forth in claim 11, whereinthe spare area full flag information comprises information of at leasttwo bits indicating whether the spare areas of the recording layers mustbe used together irrespective of the recording layers or used separatelyon a layer-by-layer basis.
 13. The high-density multi-layer optical discas set forth in claim 12, wherein the management information indicatesthat a data recording operation for a spare area can be omitted if datato be recorded in the spare area is audio/video (A/V) data, and that thedata recording operation for the spare area can be performed if the datato be recorded in the spare area is predetermined information data otherthan the A/V data.
 14. The high-density multi-layer optical disc as setforth in claim 11, wherein the DDS information comprises information ofat least two bits indicating whether the spare areas of the recordinglayers must be used together irrespective of the recording layers orused separately on a layer-by-layer basis, separated from the spare areafull flag information indicating whether each of the spare areas isfull.
 15. The high-density multi-layer optical disc as set forth inclaim 14, wherein the management information indicates that a datarecording operation for a spare area can be omitted if data to berecorded in the spare area is audio/video (A/V) data, and that the datarecording operation for the spare area can be performed if the data tobe recorded in the spare area is predetermined information data otherthan the A/V data.
 16. A method for data performing a defect managementoperation on a high-density multi-layer optical disc, the methodcomprising: (a) reading disc definition structure (DDS) informationrecorded in at least one specified area of the high-density multi-layeroptical disc, and storing the read information in a memory, wherein thedisc definition structure information includes control information forindicating whether use of the spare areas for defect management isrestricted to respective assigned layers or is layer-unrestricted; (b)determining whether use of the spare areas for defect management islayer-restricted or is layer-unrestricted based on the controlinformation; and (c) remediating a defect according to a result of thedetermination.
 17. The method as set forth in claim 16, wherein the step(b) is carried out by searching for and confirming the controlinformation contained in a field of the DDS.
 18. The method as set forthin claim 16, wherein the step (c) is carried out by referring to thecontrol information contained in the DDS information and only anarbitrary recording layer according to the result of the determination.19. The method as set forth in claim 16, wherein the step (c) is carriedout by referring to the control information contained in the DDSinformation and for the recording layers according to the result of thedetermination.
 20. The method as set forth in claim 19, wherein the step(c) comprises the steps of: (c-1) detecting a defect within a data areaof the high-density multi-layer optical disc; (c-2) searching for andconfirming spare area management information from the read DDSinformation, when the defect is detected; (c-3) determining whether useof the spare areas for defect management is layer-restricted or islayer-unrestricted, according to the confirmed spare area managementinformation; and (c-4) generating a defect list (DFL) entry needed formanaging the defect and recording the generated DFL entry to manage therecorded DFL entry, when the data is recorded in an arbitrary sparearea.
 21. A method for managing spare areas of a high-densitymulti-layer optical disc, the method comprising: (a) detecting a defectwithin a data area of the high-density multi-layer optical disc; (b)confirming spare area management information read from a lead-in area ofthe high-density multi-layer optical disc, when the defect is detected;and (c) determining whether spare areas separately assigned to a currentrecording layer must be used together with other spare areas separatelyassigned to another recording layer or only the spare areas of thecurrent recording layer must be used separately, according to theconfirmed spare area management information.
 22. The method as set forthin claim 21, wherein the step (b) is carried out by confirming the sparearea management information within disc definition structure (DDS)information read from the lead-in area of the high-density multi-layeroptical disc.
 23. The method as set forth in claim 21, furthercomprising the steps of: (d) generating a defect list (DFL) entry neededfor managing the defect and recording the generated DFL entry to managethe recorded DFL entry, when the data is recorded in an arbitrary sparearea.
 24. A high-density multi-layer optical disc having a plurality ofrecording layers formed thereon, the optical disc comprising: arespective inner spare area and a respective outer spare area assignedto each data area, each data area being assigned to a respective one ofthe recording layers; and management information, additionally recordedin a lead-in area, indicating whether use of the spare areas for defectmanagement is restricted to respective assigned layers or islayer-unrestricted.
 25. A method for managing spare areas of ahigh-density multi-layer optical disc, the method comprising: (a)detecting a defect within a data area of the high-density multi-layeroptical disc; (b) confirming spare area management information read froma lead-in area of the high-density multi-layer optical disc, when thedefect is detected; and (c) determining whether use of spare areas fordefect management is restricted to respective assigned layers or islayer-unrestricted according to the confirmed spare area managementinformation.